CAR-T技术在血液肿瘤的治疗中显示出前所未有的疗效，然而高复发率是一个亟待解决的临床难题。申请者所在的研究中心前期临床数据显示：复发的部分患者中存在JAK1/2的功能性杂合突变。已知JAK1/2突变是多个免疫检查点抑制剂治疗产生抗性的机制之一。基于此，我们提出假说：JAK1/2功能性的突变是CAR-T细胞治疗复发的一种潜在机制。本项目拟用CRISPR/Cas9技术构建具有JAK1/2功能性杂合突变的血液肿瘤细胞系及异种移植小鼠模型，观察JAK1/2突变对CAR-T杀瘤效应的影响。再利用我中心CAR-T治疗复发患者的标本，RNA-seq结合生物信息学分析筛选差异表达基因，在细胞系中诱导或沉默其表达，筛选其下游分子靶点/通路。通过纠正信号传导途径的基因缺陷，恢复肿瘤细胞表面免疫检查点分子配体的表达，达到减少疾病复发的目的。本项目有望为减少CAR-T复发提供一种新的治疗策略和机制探索。

CAR-T technology in the treatment of hematological malignancies showed an unprecedented effect, however, a high recurrence rate is an urgent clinical problem to be solved. Previous clinical data of the applicant's research center showed that there was a functional heterozygous mutation of JAK1 / 2 in some patients who relapsed. JAK1 / 2 mutations are known to be one of the mechanisms by which multiple immune checkpoint inhibitor treatments develop resistance. Based on this, we propose a hypothesis that functional mutations in JAK1 / 2 are a potential mechanism for the relapse of CAR-T cells. This project intends to use CRISPR / Cas9 technology to construct hematological tumor cell lines and xenograft mice model with JAK1 / 2 functional heterozygous mutation and to observe the effect of JAK1 / 2 mutation on CAR-T killing effect. The RNA-seq combined with bioinformatics analysis was used to analyze the recurrent specimens from patients with CAR-T in our center. The differentially expressed genes were screened and induced or silenced in cell lines to screen for their downstream molecular targets / pathways. By correcting the genetic defects of signal transduction pathways and restoring the expression of molecular ligands on the immune checkpoint on the surface of tumor cells, the purpose of reducing disease recurrence is achieved. This project is expected to provide a new therapeutic strategy and mechanism to reduce the recurrence of CAR-T.